Electric power production plants based on solar radiation can use diverse types of solar collectors (cylindrical-parabolic collector, Stirling dish, central towers with heliostats, Fresnel collectors, etc.) and all of them require support modules for the mirrors or reflectors that are responsible for concentrating solar radiation.
Generally, the collectors have a supplementary device known as a solar tracker, which allows them to orient themselves towards the sun, resulting in high performances.
The invention claimed herein refers to the support module for a solar collector, the solar tracker, which can be attached later not being an object of the invention.
Many of the inventions of the state of the art describe lattice modules that support collectors of the cylindrical-parabolic type. Cylindrical-parabolic collectors for collecting the sun's energy, use cylindrical-parabolic shaped mirrors. An absorber pipe or tube, through which a heat transfer fluid circulates, passes through the focus of the parabola, where the fluid is heated upon receiving the concentrated sun rays. Once the fluid is heated, which reaches temperatures close to 400° C., if said fluid is steam, it is sent directly to a turbine to produce electricity or, if it is another type of heat transfer fluid, which is not in vapor phase at said temperature, then it is sent to a heat exchanger for the production thereof.
Regarding its geometry, a single collector of the cylindrical-parabolic type is formed by a plurality of modules. Each one of these modules comprises a support structure, a cylindrical-parabolic reflector and an absorber tube.
All the support modules are formed by two types of elements. The first type comprises a set of elements called structural members or main structure, responsible for making the assembly rigid and withstanding the torsional and bending forces, which the whole collector assembly is subjected to. The second type comprises all those elements called supplementary elements or auxiliary structures, responsible for simply balancing the assembly and supporting the weight of the mirrors (reflector) or of the absorber tube.
Within the structural elements are the chords, posts, arms and the connections between them. The chords are the bars or elements that run longitudinally through the entire module. The arms are transversal to the chords and provide the necessary curvature for the cylindrical-parabolic reflector. The posts are located in vertical position (with greater or lesser inclination) and are connected to the chords at the nodes or connections. Furthermore, there may be secondary structural elements depending on how the module design is conceived. For example, bracing bars may be added, limiting the buckling length of the main elements.
The purlins and supports of the absorber tube are included among the supplementary elements. The purlins are installed on the arms and hold the mirrors. The supports of the absorber tube are elevated vertically over the focus of the parabola and support the tube at the exact height for the correct concentration of the solar rays that the mirrors reflect, on to the heat transfer fluid that runs through the tube.
There is a vast amount of state of the art relating to the support structures of solar collector modules, such as U.S. Pat. No. 6,414,237, U.S. Pat. No. 5,069,540, ES2326303, ES2161589, CA1088828, EP0082068, U1070880 among others.
Specifically, the patent WO2008039233A2 “Space frames and connection node arrangement” by GOSSAMER SPACE FRAMES describes a movable armature for a curved reflector of those known as double-layered, so called for having two surfaces, parallel or not, but placed at different heights.
In this structure, among the structural elements, are the following:                the bottom layer formed by two bottom major chords (51, 52), parallel one another, and parallel to the curvature axis of the reflector, the length of which being equal to the total length of the module;        the top layer of the structure formed by three upper chords, one central (57) and two outer (58, 59) the central chord being on a different plane to that of the outer chords, to configure the required curvature of the reflector;        minor chords of the bottom layer (53) and minor chords of the upper layer (61) which are placed transversally to the major chords;        struts (62) that diagonally connect the upper major chords (57, 58, 59) with the bottom major chords (51, 52);        node connectors that connect each major chord (51, 52, 57, 58, 59) with the minor chords (53) and the struts (62),        torsion braces (92) diagonally connecting the chords (58) and (59) with the chord (57), as well as diagonally connecting the major chords (51, 52) of the bottom layer;        diagonal members or struts (60) that connect the major chords (51, 52) of the bottom plane with the central major chord of the upper plane (57).        
Among the supplementary elements, the invention describes:                some reflector mounting members (99) on the minor chords, which define a curved surface that follows the curvature of the reflector;        some extended reflector support outriggers or members (100) that protrude out of the upper outer chords (58, 59) and involve an elongation, with a different angle, of the minor chord of the upper layer (61).        absorber tube supports (90) that require bars (95, 96) to stabilize said support and connect it to the base.        
In view of the state of the art, the invention claimed herein is intended to provide a module that serves as a support for a solar collector of cylinder-parabolic type and that, even despite being formed by a reticular structure of nodes and bars, has a series of characteristics that make it substantially different from those known in the state of the art, providing significant advantages both of structural strength and cost reduction in transport and assembly, all thanks to the simplification of the elements known as structural elements, i.e. those that support the loads and forces of the assembly of the collector.